Manufacturers of a wide variety of products currently employ a material resupply technique, commonly referred to as `pull manufacturing`, to replenish parts or materials required by an assembly line-side workstation in the course of its participation in the production of an item of manufacture. A reduced complexity illustration of such a conventional pull manufacturing scheme is diagrammatically illustrated in FIG. 1 as comprising a plurality of line-side workstations, two of which are shown as workstations 1 and 2, that are distributed along an assembly line served by a conveyor 3. As an item 4 being assembled is conveyed along the assembly line, each workstation performs a respective subassembly operation that incorporates one or more parts or materials into the item. Thus, as shown at workstation 1, a part 41 is installed into the item; next, at a workstation 2, downstream of workstation 1, a part 4.sub.2 is added to the partially assembled item, and so on down the assembly line.
In accordance with conventional `pull manufacturing` material replenishment, the components at any given workstation, shown in FIG. 1 as contained in local inventories of parts 4.sub.1 and 4.sub.2, respectively associated with line side sites 1 and 2, are updated in response to a request or `call` from the workstation to a remote storage management and distribution subsystem. In response to the part request, the storage management and distribution subsystem then retrieves some number of the requested part from an off-line storage facility and delivers them to the requesting site.
In order for such an `optimal efficiency` pull manufacturing replenishment scheme to be successful, it must be reliable, flexible and provide `on-time` delivery. Unfortunately, within most of today's manufacturing environments, options for communicating material replenishment requests to those responsible for delivering the parts to a line-side workstation are considerably limited. A significant number of production facilities continue to employ traditional manual, labor-intensive routines, such as card-based methods. Others, which have attempted to incorporate upgraded communication methods, use hardwired subsystems, that are not only costly to install but, due to their inherent inflexibility, are expensive, time consuming, and labor intensive to retrofit or modify, as the needs and/or retooling of the plant are continually being updated and reconfigured. Although some wireless call systems have been proposed, they are complex, requiring two-way communications with a line-side location, and are thus extremely expensive to install and operate.